The present invention relates generally to piezoelectric based assemblies and devices. More particularly, the present invention provides improved methods, and related systems and devices, for fabricating selectively patterned piezoelectric substrates suitable for use in a wide variety of systems and devices.
Piezoelectric substrates produce a displacement with a force capability when voltage is applied. Many applications exist where a piezoelectric substrates may be used, including precision positioning, generation of forces or pressures in static or dynamic situations, voltage/power generation, and numerous sensors, actuators, and the like. One important application of piezoelectric substrates includes use in piezoelectric based actuators. As applied voltages correspond to precise changes in the width/shape of the substrate, width can be changed with very high precision, making piezo substrates an important tool for positioning objects with extreme accuracy—thus their use in actuators.
Actuator configuration and design can vary greatly depending on application. Piezoelectric stack actuators, for example, are produced by stacking up piezoelectric substrate disks or plates, with the axis of the stack being the asis of linear motion when a voltage is applied. Actuators can further include tube-shaped actuators, which commonly include a monolithic substrate that contracts (e.g., laterally, longitudinally) when voltage is applied between inner and outer electrodes. Other exemplary configurations include disk and ring shaped actuators, as well as block, bender, and bimorph styles.
Piezoelectric based actuators have found use in numerous systems, including various optical image acquisition systems. One example of such systems making use of piezo actuator assemblies includes certain recently developed improved scanning beam systems. These improved scanning beam systems are typically much smaller than conventional devices, and make use of a cantilevered optical fiber that can be scanned in one or more dimensions. Light is projected out of the end of the optical fiber, through a optical/lens system, and onto a target area of a surface. To acquire an image, a time series of backscattered reflected light is captured with one or more light detector(s) of the system. More specifically, signals from one or more photodetector(s) correspond to the brightness of the small portion of the image illuminated by the fiber at that point in time. As the motion of the optical fiber is predictable and repeatable, the reflected backscattered light intensity measured at the detector(s) can be sequentially correlated with known positions of the optical fiber. This allows a two-dimensional image to be generated one pixel at a time. Some exemplary scanning fiber devices are described in U.S. Pat. No. 6,294,775B1 (Seibel) and U.S. Pat. No. 6,563,105B2 (Seibel), and in U.S. Patent Application Publication Nos. 2001/0055462A1 (Seibel) and 2002/0064341A1 (Seibel), the complete disclosures of which are incorporated herein by reference.
While piezo actuator configuration and design can vary greatly depending on application, devices typically includes a substrate including a piezoelectric material, where the substrate is coupled with electrodes that are often patterned on one or more substrate surfaces. Although various configurations and designs of patterned piezoelectric substrates are known, substrate patterning and fabrication is typically tedious and often inefficient. Commonly used methods often involve complex masking and/or patterning techniques including numerous steps and processes, that can be time consuming, costly, and/or inaccurate. Therefore, what is needed are fabrication techniques and resulting devices, that are more easily and effectively performed for production of precision patterned piezo substrates for use in a variety of applications.